of the waves. Harry's motorboat was near
and he was standing in the bow, scanning the water with binoculars.

"And he can't see us?" asked Pauline.

"Oh, yes, he'll pick up out periscope after a while. Shall we fire
the torpedo at him?"

"Yes, please," said Pauline.

Summers' laugh was cut short. As if someone had taken his jest in
earnest and really fired a projectile, the crash of an explosion came
from the bottom of the boat.

"Stay here--" ordered Summers with a set face as he joined the rush of
seamen into the pump room.

But Pauline followed.

An officer, with blanched face but steady voice, came up to Summers.

"What was it, Grimes?"

"It seems to have been a bomb, sir. There was no powder down there."

The face of the Ensign darkened with suspicion and alarm.

"A bomb? So they were going after us--the enemy! We'd better get
right up and back to port, Grimes."

"I have to report, sir--the pumps are disabled."

Summers turned with a look of pity toward Pauline, who stood at his
elbow.

"And we can't get up again?" she questioned.

"There is one chance, but--" He stopped openly and listened. "Open
that locker," he commanded.

A seaman pulled back the door of the locker and disclosed the cringing
form and defiant face of Catin.

"Catin! You!"

The man stepped forward with a smile of triumph.

"You set off the bomb? You wanted to kill me?"

"I did my duty. I obeyed my orders as you obey your orders. I had no
enmity for you. I am, in fact, sorry that you were fool enough not to
see that I was a little more than a valet."

"You are a spy, Catin?"

"Yes, sir. And I have done my work, and I am willing to die with the
rest of you."

Pauline drew back, shuddering. She touched Summers' arm.

"Oh, Mr. Summers, I believe--"

"What is it?"

"I believe I know of the plot. I was in the conservatory at the naval
ball. A man and a woman--"

"A woman?"

"Mlle. de Longeon and her diplomatic friend--you remember."

"Yes--well?"

"They talked together in whispers. The man said 'The thing will be
done on Submarine B-2 tomorrow.'"

A look of agony that the fear of death could not have caused came into
the face of the young Ensign.

"Mlle. de Longeon? No!"

"Yes! Mlle. de Longeon," sneered Catin stepping nearer. "Mlle. de
Longeon is the principal proof of my statement that you are a fool.
Mlle. de Longeon recommended me to you as a capable valet, did she
not? Mlle. de L